For people whom me and cheryl personally sms-ed:
If you did not reply whether you want to join Earth Hour or SPD flag day, you'll be automatically placed into flag day, as today was the end of the registration for Earth Hour.

More info:
      Earth Hour- 27March'10
                   12.30pm to 6pm/10pm
SPD Flag Day - 10April
                        10am to 3pm

Dont Worry, any changes will be made through blog/noticeboard
just check the blog for more updates! ;D